//Propiedad de Click derecho verifica el tipo de navegador. 
var ns4 = (document.layers)? true:false 
var ie = (document.all)? true:false 
var ns6 = (document.getElementById && !document.all) ? true: false; 
var coorX, coorY; 
if (ns6) document.addEventListener("mousedown", coord, true) 
if (ns4) {document.captureEvents(Event.MOUSEDOWN); document.mousedown = coord;} 
if (ie) document.onmousedown = coord

function coord(e)
{
   if (ns4||ns6)    { 
      coorX = e.pageX; 
      coorY = e.pageY; 
   } 
   if (ie)    { 
      coorX = event.x; 
      coorY = event.y; 
   } 
   if (document.layers && !document.getElementById){ 
     if (e.which == 2 || e.which == 3){ 
      mostrar()
      return false; 
     } 
    } 

   return true;
}
function mostrar()
{ 

   with(document.getElementById("menu"))    { 
      style.top = coorY + 10; 
      style.left = coorX + 10; 
      style.visibility = "visible"; 
   } 
   return false
} 
function ocultar()
{ 
   document.getElementById("menu").style.visibility = "hidden"; 
} 
document.oncontextmenu=mostrar
//Ya dejamos el chiqueo.